Multiple push-button switch assembly with interlocking mechanism

Abstract

This invention is an interlocking device for a push-button switch in compact size and with a mechanically simple construction, capable of realizing interlocking of a push-button switch having a pair of push buttons facing each other and being downwardly movable in multiple stages by being pressed, while sufficiently securing stroke in each stage of the push buttons. A switch body having a fixed contact is provided with two push buttons, having mobile contacts, facing each other and being downwardly movable in multiple stages. An interlocking member for mobile contact is swingably disposed, for preventing closing of the mobile contact of at least one push button due to touching of the mobile contact the two push buttons are pressed, on the switch body at a position lower than the push buttons, with approximately the mid-point of two push buttons.

I claim: 
     
       1. An interlocking device for a push button switch, the push button switch including a switch body with fixed contacts, the push button switch having first and second push buttons which are downwardly movable in multiple stages by being pressed, each of the first and second push buttons having mobile contacts, said interlocking device comprising: a mobile contact interlocking member for preventing the contact of a mobile contact of at least one of the push buttons with a corresponding fixed contact when the first and second push buttons are pressed down simultaneously;   said mobile contact interlocking member being provided on the switch body so that said mobile contact interlocking member swings on the switch body at a position which is relatively lower that the first and second push buttons; and   said mobile contact interlocking member being connected to the switch body at approximately a mid-point between the first and second push buttons.   
     
     
       2. The interlocking device as described in claim 1 further comprising: an interlocking member for preventing closing of the push buttons and for preventing the push buttons from being simultaneously pressed down by no less than two stages;   said interlocking member being provided on the switch body so that said interlocking member swings on the switch body at a position which is relatively lower that the first and second push buttons; and   said interlocking member being connected to the switch body at approximately a mid-point between the first and second push buttons.   
     
     
       3. An interlocking device for a push button switch, the push button switch including a switch body with fixed contacts, the push button switch having first and second push buttons which are downwardly movable in multiple stages by being pressed, each of the first and second push buttons having mobile contacts, said interlocking device comprising: a first interlocking member corresponding to the first push button, said first interlocking member including a projection;   a second interlocking member corresponding to the second push button, said second interlocking member including a projection; and   said first and second interlocking members facing each other and being synchronizingly swingable when the push buttons are pressed down; wherein   when one of the push buttons is pressed down, said projection of the interlocking member corresponding to the pressed down push button prevents the swinging of the other interlocking member thereby preventing any simultaneous pressing down of the push buttons.   
     
     
       4. A push button switch comprising: a switch body with fixed contacts;   first and second push buttons which are downwardly movable in multiple stages by being pressed, each of said first and second push buttons having mobile contacts;   an interlocking device comprising a mobile contact interlocking member for preventing the contact of a mobile contact of at least one of said push buttons with a corresponding fixed contact when said first and second push buttons are pressed down simultaneously;   said mobile contact interlocking member being provided on said switch body so that said mobile contact interlocking member swings on said switch body at a position which is relatively lower that said first and second push buttons; and   said mobile contact interlocking member being connected to said switch body at approximately a mid-point between said first and second push buttons.     
     
     
       5. The push button switch as described in claim 4, wherein the interlocking device further comprises: an interlocking member for preventing closing of said push buttons and for preventing said push buttons from being simultaneously pressed down by no less than two stages;   said interlocking member being provided on said switch body so that said interlocking member swings on said switch body at a position which is relatively lower that said first and second push buttons; and   said interlocking member being connected to said switch body at approximately a mid-point between said first and second push buttons.   
     
     
       6. A push button switch comprising: a switch body with fixed contacts;   first and second push buttons which are downwardly movable in multiple stages by being pressed, each of said first and second push buttons having mobile contacts;   an interlocking device comprising a first interlocking member corresponding to said first push button, said first interlocking member including a projection;   a second interlocking member corresponding to said second push button, said second interlocking member including a projection; and   said first and second interlocking members facing each other and being synchronizingly swingable when said push buttons are pressed down; wherein   when one of said push buttons is pressed down, said projection of the interlocking member corresponding to the pressed down push button prevents the swinging of the other interlocking member thereby preventing any simultaneous pressing down of said push buttons.